Masha had participated in 2 Olympiads before Monday.

И

Korean students get to school by train.

Переделать эти предложения во все времена группы Present, Past и в Future Simple.

Until Monday, Masha participated in two Olympiads.

Until Monday, Masha is participating in two Olympiads.

Until Monday, Masha will participate in two Olympiads.

Korean students travel to school by train.

Korean students traveled to school by train.

Korean students will travel to school by train.